Tag Archives: Advanced PostgreSQL tutorial

[Solved] PostgreSQL Error: Could not connect to server: no such file or directory

1. Problem description

when operating PostgreSQL database service, an error message is received: 

Could not connect to server: no such file or directory

2. Solution

PostgreSQL error message “could not connect to server: no such file or directory” it is known that it is caused by the problem of postmaster

the error message indicates that PostgreSQL is not running in the system where the user logs in. When handling this common error, check “postmaster.PID” in the data directory. Ensure that the configuration of PostgreSQL allows TCP/IP connections

[PostgreSQL tutorial] · PostgreSQL error prompt: “error 42501” or “permission denied”

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1. Problem overview 2. Solution

1. Problem overview

log in to the PostgreSQL database service with the PSQL command. When querying data, you receive an error log prompt, as follows: 

“Error 42501” or “Permission Denied”

2. Solution

PostgreSQL error code 42501 is a common error, which sometimes occurs when responding to PostgreSQL database queries. In most cases, the error code 42501 indicates that the user has insufficient permissions on the database. PostgreSQL responds with an error message whenever a user with insufficient permissions makes a query

to solve this problem, please check the database user permissions. If the user trying to query lacks permission, just change the permission accordingly. You can use “ grant select on table_name to public; ” to grant permission to the public. Or use the command “ grant select on table_name to user_name; ” for only a few users

[PostgreSQL tutorial] · out of memory issue

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1. Problem description 2. Solution

1. Problem description

the PostgreSQL server running on the server receives an error log prompt message: 

ERROR: out of memory 2021-11-24 
DETAIL: Failed on request of size 1880.

2. Solution

the memory of each system is limited. When there is no memory left, PostgreSQL’s memory allocation function begins to fail. Please check your hardware configuration and limitations